The structure of organic electroluminescent devices (OLEDs) in which organic semiconductors are employed as functional materials is described, for example, in U.S. Pat. Nos. 4,539,507, 5,151,629, EP 0676461 and WO 98/27136. The emitting materials employed here are increasingly organo-metallic complexes which exhibit phosphorescence instead of fluorescence (M. A. Baldo et al., Appl. Phys. Lett. 1999, 75, 4-6).
In accordance with the prior art, the hole-transport materials used in the hole-transport layer or in the hole-injection layer are, in particular, triaryl-amine derivatives which frequently contain at least two triarylamino groups or at least one triarylamino group and at least one carbazole group. These compounds are frequently derived from diarylamino-substituted triphenyl-amines (TPA type), from diarylamino-substituted biphenyl derivatives (TAD type) or combinations of these base compounds. Furthermore, for example, use is made of spirobifluorene derivatives which are substituted by one to four diarylamino groups (for example in accordance with EP 676461, U.S. Pat. No. 7,714,145).
In EP2814906, spirobifluorene derivatives substituted with a diarylamine group in position 1, 1′, 8 or 8′ are represented.

The use of spirobifluorene derivatives substituted in position 1, 1′, 8 or 8′ in OLEDs is interesting because it leads to OLEDs with good properties, in particular in terms of efficiency and operating voltage.
In the case of these compounds, there is still a demand for alternative materials that can be used in OLEDs devices in order to obtain devices with good properties, in particular in terms of efficiency.
However, it is difficult to synthesize such compounds because the positions 1, 1′, 8 or 8′ are difficult to access.
Therefore, there is also a demand for processes for the preparation of these compounds with higher reaction yields, in order to reduce the fabrication costs. There is also a demand for processes, which are easy to implement and which enable to obtain compounds with a high purity. The intermediate compounds play a key role in the synthesis of materials for OLEDs. It is important to have some intermediate compounds, which are stable, easy to synthesize and easy to purify in order to increase the efficiency of the synthesis of the OLED materials and thus, to decrease the costs of the synthesis. Intermediate compounds that are stable, easy to synthesize and easy to purify are even more interesting when then can be used in different kind of syntheses in order to obtain different kind of OLED materials.